Gusto.7z

Could you clarify or if it was part of a specific security alert ? Does 7z compress better than zip? - Microsoft Community Hub

Given the name, it is most likely a created by an individual or organization using the 7-Zip utility. Depending on the context in which you encountered it, "Gusto" likely refers to one of the following:

: It could be a local backup of data related to Gusto , a popular HR and payroll platform .